Pump



L. F. MOODY Dec. 29, 1942.

PUMP

llllllll Filed June 26, 1940 Lewis FT Mandy INVENTOR ATTORNEY Patented Dec. 29, 1942 embodying the invention, and the tea Q gen Fi zeoeuz so that :axia ,yel

P'E'SSB' into th'e impelleaandth I SlICHOYIiZsbacE just guie z -or:.;the, amwirig", ,i1,v ii of the vanes 5 are straight direction or liouidriiow throng d-intooth mue er 2 The guideiv 'str tiongzare;rotatahlydlll tabl ing the i-nvention be specifically pointed outta in the claim;

In the drawing:

Figure 1 is a vertical section trifugal pump having the improved capacity regulating vanes associated therewith.

Figure 2 is a vertical section through the inlet connection of the pump taken on line 22 of Figure 1, and at right angles to the section shown in Figure 1.

Figure 3 is a side elevation of the inlet connection of the pump.

through a cenlen'g'tht i-I attach each vane ii t h tito ai slightlyinoneax ldi protuberancea onothefeva 116" "at asrelatively smalhangl ialrlortwhirl-icomponen to to adjustthe capacity; an A H purhp overiira: limitedgrange, and a ucticin cinlet' -member;

new the vanes 5 relatively thin throughout, their hroughout it"s' laxial 'i'len'gth to a portion ofv the 1 casingQ-yvall, preferably Referring more particularly to the drawing, a

vertical type of centrifugal single stage pump of the impeller type is shown, but it is totbje understood that the invention may be applied with equal practicability to double suction or multistage horizontal pumps, and to pumps of either the propeller or impeller type, without departing from the spirit of the present invention.

The centrifugal pump includes the casing l, in which an impeller 2 is rotatably mounted, receiving the liquid pumped through the suction inlet 3 and discharging it into the volute 4. The suction inlet passage 3 of said casing l is of substantially the same diameter as the suction eye or inlet 6 of the impeller 2, with walls 3' having a continuous con-tour from the inlet of the suction passage through to the impeller chamber,

casting each vane integrally with saidpo'rt'ion of the casing or inlet member wall. To permit the rotary adjustment of the vanes 5, the wall portion or disk 1, attached to or forming part of the vane I, is formed as a circular disk, recessed in the surrounding portion of the wall 3' so that its surface is continuous with the rest of said wall.

Spindles 8 are rigidly attached to said wall portion or disk I exteriorly of the inlet member-3 and have operating handles 9 attached to their outer ends, by means of which the vanes 5 are rotated on axes transversally of the axis of rotation of the impeller 2. A quadrant I0 is provided, and a locking latch H is carried by the handle 9 for engagement in the various detents l2 formed in the quadrant ID, for securely holding the vanes 5 inradjusted positions.

At times it is found that a centrifugal pump is slightly excessive or deficient in capacity, and heretofore various methods have been resorted to for correction thereof, such as by cutting back the impeller vanes. However, with the present type of control vanes 5, the capacity and head of the pump can be regulated as desired. By rotat- .ing the vanes 5 forward, a positive initial whirl will be imparted to the liquid entering the suction mam-a d mak a eye 6 of the impeller 2, which will reduce the capacity of the pump. Conversely, by turning the vanes to give a negative whirl, via. a whirl opposite to the impeller rotation, the head and capacity oi the pump can be increased.

The vanes 5 may have a curved contour for use with an impeller designed for initial whirl at normal capacity.

If the vanes 5 were rotated through a large angle of adjustment, the wall portion or surface of the disk I would then become discontinuous with the rest of the wall 3' of the suction inlet member 3, but since only a limited angular adjustment (of the order of not over 30) will be suflicient in practice to provide the required adjustment of capacity and head, this degree of discontinuity will be negligible.

The method of supporting the vanes 5 as described provides suflicient area where the vane 5 joins the disk 1 to permit the vane 5 being made relatively thin and still provides suflicient strength without interference with the flow.

Although in the construction shown only two of said vanes 5 are shown, it is to be understood that any number of said vanes may be employed, as desired to effect the proper adjustment of the pump, without departing from the spirit of the present invention.

By placing the vanes in a passage of substantially the same diameter or size as the impeller inlet, they influence the flow where the velocity is high enough to make their control effective.

It is important that the suction passage be symmetrical about the impeller axis, without curvature of its center line, for a substantial distance from the impeller, and that no curvature of the passage centerline occur within a distance from the impeller entrance equal to about the radius of the impeller, in order to provide that all guide vanes act on flow which has substantially the same velocity, so that all parts of the impeller will act similarly and with equal efficiency. Otherwise, sidewise flow components and unstable and unsatisfactory operation could occur.

It will be understood that the invention is not to be limited to the specific construction or arrangement 01 parts shown, but that they may be widely modified within the invention defined by the claim.

What is claimed is:

In a centrifugal pump, a casing having a centrally disposed inlet opening at one side thereof and a discharge volute disposed with its axis at right angles to the axis of the inlet, an impeller in said casing and having its inlet opening into the inlet 0! said casing and its discharge opening into said volute, a suction passage member attached to said casing and having its outlet of substantially the same diameter as the inlet oi the impeller, the suction passage member being free of any obstructions therein, a disc forming a part of and rotatably carried by the wall of said suction passage member, a capacity regulating vane carried by said rotarydisc, the diameter of said disc being equal to the maximum width or said vane to provide strengthening oi the edge portions. of the vane and protect the edges oi the vane against detrimental action of hydraulic stresses, said vane extending radially into the suction passage member a short distance outwardly from theoutlet of the suction passage member,

said capacity regulating vane being straight with plane central surfaces and normally lying in the plane or liquid flow through the suction passage so as to provide unobstructed flow of fluid through the passage, means connected to said vane for rotating the vane on an axis transversely of the axis of rotation of the impeller and transversely to the directional flow of fluid through the suction passage member whereby when the vane is rotated in one direction a positive whirl will be imparted to the liquid flowing to the impeller to reduce the head and capacity of the pump and when the vane is adjusted in a reverse direction a negative whirl will be-imparted to liquid flowing to the impeller for increasing the head and capacity of the pump, and means connected to said disc and projecting exteriorly oi the suction passage member whereby the vane may be regulated during operation of the pump.

LEWIS F. MOODY. 

